

A269163


Numbers which have a finite predecessor in Wolfram's Rule 30 cellular automaton; range of A269160 sorted into ascending order.


6



0, 7, 13, 14, 25, 26, 27, 28, 49, 50, 51, 52, 53, 54, 56, 63, 97, 98, 99, 100, 101, 102, 104, 105, 106, 107, 108, 111, 112, 119, 125, 126, 193, 194, 195, 196, 197, 198, 200, 201, 202, 203, 204, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 221, 222, 223, 224, 231, 237, 238, 249, 250, 251, 252, 385, 386, 387, 388
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OFFSET

0,2


COMMENTS

Numbers which have a finite predecessor in Wolfram's Rule 30 cellular automaton. The configuration of white and black cells is encoded in the binary representation (A007088) of each number.
The indexing starts from zero, because a(0) = 0 is a special case in this sequence. (Zero is the only number which is its own predecessor).


LINKS

Antti Karttunen, Table of n, a(n) for n = 0..8191
Eric Weisstein's World of Mathematics, Rule 30
Index entries for sequences related to cellular automata
Index to Elementary Cellular Automata


MATHEMATICA

terms = 100; Clear[f]; f[max_] := f[max] = Sort[Table[BitXor[n, BitOr[2n, 4n]], {n, 0, max}]][[1 ;; terms]]; f[terms]; f[max = 2 terms]; While[ Print[max]; f[max] != f[max/2], max = 2 max]; A269163 = f[max] (* JeanFrançois Alcover, Feb 23 2016 *)


PROG

(Scheme, with Antti Karttunen's IntSeqlibrary)
(define A269163 (MATCHINGPOS 0 0 (lambda (n) (or (zero? n) (not (zero? (A269162 n)))))))


CROSSREFS

Complement: A269164.
Cf. A007088, A269162.
Sequence in context: A120100 A308525 A104217 * A260482 A328254 A191976
Adjacent sequences: A269160 A269161 A269162 * A269164 A269165 A269166


KEYWORD

nonn


AUTHOR

Antti Karttunen, Feb 20 2016


STATUS

approved



